There was a stuck cache issue that I addressed this morning
(cache invalidation logic). Looks like the docs are updating now.
Let me know if that output doesn't look right or if this happens
again. I'll be working on overhauling our caching strategy soon,
apologies for the inconvenience.

We clean up the repos we checkout to remove all the "source
code" after YARD has processed it so we can save on disk space. We
end up saving ~80% of the project's size this way, which can be in
the order of mb for some projects. This adds up over the tens of
thousands of projects we have checked out.

All that to say-- in order for YARD to detect "extra files"
(what we call those readme things), those files need to be
specified in the .yardopts. Incidentally that's also how YARD
detects extra files.

The actual YARD format for specifying extra files is yard
[opts] SRC_FILES - EXTRA_FILES, noting the "-" separator.
Therefore, the .yardopts you actually want to be using
is: